I know people here have used old version promo codes on an app that was updated. Have you tested it? I do know codes expire after 28 days. http://www.ismashphone.com/2009/06/how-to-use-app-store-promo-codes.html # 50 codes per app. (each time the app is updated the number of codes goes back to 50) # One time use. (each code can only be used once) # Codes expire after 28 days. # US only. # Codes can be used before app goes live in the App Store, as long as Apple has approved your application. # Developers must agree to Apple's terms of conduct before being allowed to use codes. The purpose is to promise not to sell the codes personally, cutting out Apple's 30%.
You can use older codes for newer versions, until the day limit. You just need to make sure you've downloaded all 50 codes before the new update comes out, or you won't be able to grab them, as they'll be replaced with a new set of 50.
I BUY AND REVIEW MY OWN GAME!!! Sorry for shouting but I'm proud of it and never regret my review on iTunes. In my review I only point out the positive not saying anything about negative side. I know it is a little bias but at least I'm not lying.
DaveMc99 hit the nail on the head, the codes arent version based, they are base on time, however you can only get them 50 at a time for any given version.
